Search (5 results, page 1 of 1)

  • × year_i:[2000 TO 2010}
  • × author_ss:"Bar-Ilan, J."
  1. Bar-Ilan, J.: Comparing rankings of search results on the Web (2005) 0.02
    0.023530604 = product of:
      0.04706121 = sum of:
        0.02586502 = weight(_text_:data in 1068) [ClassicSimilarity], result of:
          0.02586502 = score(doc=1068,freq=2.0), product of:
            0.14807065 = queryWeight, product of:
              3.1620505 = idf(docFreq=5088, maxDocs=44218)
              0.046827413 = queryNorm
            0.17468026 = fieldWeight in 1068, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.1620505 = idf(docFreq=5088, maxDocs=44218)
              0.0390625 = fieldNorm(doc=1068)
        0.021196188 = product of:
          0.042392377 = sum of:
            0.042392377 = weight(_text_:processing in 1068) [ClassicSimilarity], result of:
              0.042392377 = score(doc=1068,freq=2.0), product of:
                0.18956426 = queryWeight, product of:
                  4.048147 = idf(docFreq=2097, maxDocs=44218)
                  0.046827413 = queryNorm
                0.22363065 = fieldWeight in 1068, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  4.048147 = idf(docFreq=2097, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=1068)
          0.5 = coord(1/2)
      0.5 = coord(2/4)
    
    Abstract
    The Web has become an information source for professional data gathering. Because of the vast amounts of information on almost all topics, one cannot systematically go over the whole set of results, and therefore must rely on the ordering of the results by the search engine. It is well known that search engines on the Web have low overlap in terms of coverage. In this study we measure how similar are the rankings of search engines on the overlapping results. We compare rankings of results for identical queries retrieved from several search engines. The method is based only on the set of URLs that appear in the answer sets of the engines being compared. For comparing the similarity of rankings of two search engines, the Spearman correlation coefficient is computed. When comparing more than two sets Kendall's W is used. These are well-known measures and the statistical significance of the results can be computed. The methods are demonstrated on a set of 15 queries that were submitted to four large Web search engines. The findings indicate that the large public search engines on the Web employ considerably different ranking algorithms.
    Source
    Information processing and management. 41(2005) no.6, S.1511-1519
  2. Bar-Ilan, J.; Peritz, B.C.: ¬A method for measuring the evolution of a topic on the Web : the case of "informetrics" (2009) 0.01
    0.011199882 = product of:
      0.04479953 = sum of:
        0.04479953 = weight(_text_:data in 3089) [ClassicSimilarity], result of:
          0.04479953 = score(doc=3089,freq=6.0), product of:
            0.14807065 = queryWeight, product of:
              3.1620505 = idf(docFreq=5088, maxDocs=44218)
              0.046827413 = queryNorm
            0.30255508 = fieldWeight in 3089, product of:
              2.4494898 = tf(freq=6.0), with freq of:
                6.0 = termFreq=6.0
              3.1620505 = idf(docFreq=5088, maxDocs=44218)
              0.0390625 = fieldNorm(doc=3089)
      0.25 = coord(1/4)
    
    Abstract
    The universe of information has been enriched by the creation of the World Wide Web, which has become an indispensible source for research. Since this source is growing at an enormous speed, an in-depth look of its performance to create a method for its evaluation has become necessary; however, growth is not the only process that influences the evolution of the Web. During their lifetime, Web pages may change their content and links to/from other Web pages, be duplicated or moved to a different URL, be removed from the Web either temporarily or permanently, and be temporarily inaccessible due to server and/or communication failures. To obtain a better understanding of these processes, we developed a method for tracking topics on the Web for long periods of time, without the need to employ a crawler and relying only on publicly available resources. The multiple data-collection methods used allow us to discover new pages related to the topic, to identify changes to existing pages, and to detect previously existing pages that have been removed or whose content is not relevant anymore to the specified topic. The method is demonstrated through monitoring Web pages that contain the term informetrics for a period of 8 years. The data-collection method also allowed us to analyze the dynamic changes in search engine coverage, illustrated here on Google - the search engine used for the longest period of time for data collection in this project.
  3. Bar-Ilan, J.: ¬The Web as an information source on informetrics? : A content analysis (2000) 0.01
    0.010973599 = product of:
      0.043894395 = sum of:
        0.043894395 = weight(_text_:data in 4587) [ClassicSimilarity], result of:
          0.043894395 = score(doc=4587,freq=4.0), product of:
            0.14807065 = queryWeight, product of:
              3.1620505 = idf(docFreq=5088, maxDocs=44218)
              0.046827413 = queryNorm
            0.29644224 = fieldWeight in 4587, product of:
              2.0 = tf(freq=4.0), with freq of:
                4.0 = termFreq=4.0
              3.1620505 = idf(docFreq=5088, maxDocs=44218)
              0.046875 = fieldNorm(doc=4587)
      0.25 = coord(1/4)
    
    Abstract
    This article addresses the question of whether the Web can serve as an information source for research. Specifically, it analyzes by way of content analysis the Web pages retrieved by the major search engines on a particular date (June 7, 1998), as a result of the query 'informetrics OR informetric'. In 807 out of the 942 retrieved pages, the search terms were mentioned in the context of information science. Over 70% of the pages contained only indirect information on the topic, in the form of hypertext links and bibliographical references without annotation. The bibliographical references extracted from the Web pages were analyzed, and lists of most productive authors, most cited authors, works, and sources were compiled. The list of reference obtained from the Web was also compared to data retrieved from commercial databases. For most cases, the list of references extracted from the Web outperformed the commercial, bibliographic databases. The results of these comparisons indicate that valuable, freely available data is hidden in the Web waiting to be extracted from the millions of Web pages
  4. Bar-Ilan, J.: What do we know about links and linking? : a framework for studying links in academic environments (2005) 0.01
    0.0063588563 = product of:
      0.025435425 = sum of:
        0.025435425 = product of:
          0.05087085 = sum of:
            0.05087085 = weight(_text_:processing in 1058) [ClassicSimilarity], result of:
              0.05087085 = score(doc=1058,freq=2.0), product of:
                0.18956426 = queryWeight, product of:
                  4.048147 = idf(docFreq=2097, maxDocs=44218)
                  0.046827413 = queryNorm
                0.26835677 = fieldWeight in 1058, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  4.048147 = idf(docFreq=2097, maxDocs=44218)
                  0.046875 = fieldNorm(doc=1058)
          0.5 = coord(1/2)
      0.25 = coord(1/4)
    
    Source
    Information processing and management. 41(2005) no.4, S.973-986
  5. Bar-Ilan, J.; Levene, M.; Mat-Hassan, M.: Methods for evaluating dynamic changes in search engine rankings : a case study (2006) 0.01
    0.0051730038 = product of:
      0.020692015 = sum of:
        0.020692015 = weight(_text_:data in 616) [ClassicSimilarity], result of:
          0.020692015 = score(doc=616,freq=2.0), product of:
            0.14807065 = queryWeight, product of:
              3.1620505 = idf(docFreq=5088, maxDocs=44218)
              0.046827413 = queryNorm
            0.1397442 = fieldWeight in 616, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.1620505 = idf(docFreq=5088, maxDocs=44218)
              0.03125 = fieldNorm(doc=616)
      0.25 = coord(1/4)
    
    Abstract
    Purpose - The objective of this paper is to characterize the changes in the rankings of the top ten results of major search engines over time and to compare the rankings between these engines. Design/methodology/approach - The papers compare rankings of the top-ten results of the search engines Google and AlltheWeb on ten identical queries over a period of three weeks. Only the top-ten results were considered, since users do not normally inspect more than the first results page returned by a search engine. The experiment was repeated twice, in October 2003 and in January 2004, in order to assess changes to the top-ten results of some of the queries during the three months interval. In order to assess the changes in the rankings, three measures were computed for each data collection point and each search engine. Findings - The findings in this paper show that the rankings of AlltheWeb were highly stable over each period, while the rankings of Google underwent constant yet minor changes, with occasional major ones. Changes over time can be explained by the dynamic nature of the web or by fluctuations in the search engines' indexes. The top-ten results of the two search engines had surprisingly low overlap. With such small overlap, the task of comparing the rankings of the two engines becomes extremely challenging. Originality/value - The paper shows that because of the abundance of information on the web, ranking search results is of extreme importance. The paper compares several measures for computing the similarity between rankings of search tools, and shows that none of the measures is fully satisfactory as a standalone measure. It also demonstrates the apparent differences in the ranking algorithms of two widely used search engines.